1. Field of the Invention
This invention relates to improvements in a container for the transportation of semiconductor wafers. More particularly, the present wafer container includes improvements in clamping sidewalls that prevent movement to the wafers.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
In the processing of semiconductor wafers the typically must be transported either between processes or to other facilities. The semiconductor wafers are fragile and damage to the surface of the wafers can make the wafer useless for the intended purpose. Because of the high potential for damage to the wafer the semiconductors must be packaged and transported to minimize harm. In transportation, multiple semiconductor wafers are stacked into a transportation container. There have been a number of containment products and patents have been sold and patented to try and minimize damage to these silicon wafers. Exemplary examples of patents covering these products are disclosed herein.
U.S. Patent Publication Number US2006/0042998 that was published on Mar. 2, 2006 to Cliffton C. Haggard et al., discloses using a cushion insert that is placed on top of the wafers. When the lid is closed on top of the cushion insert, the support portions push on the inside of the lid. This causes the cushioning member to conform around the wafer at contact points. While this reference minimizes movement of the wafers, the wafers are stored vertically and the cushioning is applied on the closing side of the enclosure. The closing of the carrier pushes down on the cushion instead of sliding on the cushion. The cushion is further not integrated with the enclosure, and exists as a separate component.
U.S. Pat. No. 7,100,772 issued Sep. 5, 2006 to John Burns et al., disclose a containment device for retaining semiconductor wafers with several methods of pushing on the sides of a semiconductor wafer. In all of the embodiments, one half of the housing interacts with an arm located in the second half of the housing to press on the sides of the semiconductor wafer. In one embodiment, a spring loaded pistons push on branch members. In another embodiment, an arm on a living hinge is pushed to make contact with the wafer. While this patent discloses a wafer carrier that reduces movement of the wafers, the wafers are stored vertically and the cushioning is applied on the closing side of the enclosure. The closing of the carrier pushes down on the cushion instead of sliding on the cushion. This patent uses multiple arms, one for each wafer. The top housing pushed down on the cushion instead of sliding on the arms to provide the cushion.
U.S. Pat. No. 6,988,620 issued Jan. 24, 2006 to Clifton C. Haggard et al., discloses a wafer container having a top housing with sidewall tab portions that have a chamfered edge that pushes against a corresponding chamfered edge in the bottom housing to push extensions against the wafers. In this patent the hinge bends from the bottom housing and can bow whereby making contact with some but not all of the wafers. The hinge does not swing from the sidewall of the wafer carrier and the contact point on the wafers is not distal from the hinge to evenly apply the force to the wafers.
U.S. Pat. No. 5,402,890 issued Apr. 4, 1995 to Toshitsugu Yajima et al., discloses a box container with a flexible liner box member that is placed between the top and bottom housings. There are wedge like ribs that slide on the inside sidewalls that push the liner box member against the sheet bodies placed within the enclosure. The interaction of closing the housing causes deformation of one part that makes contact with all of the sheet bodies within the housing. This patent requires a separate insert to provide the cushioning and the cushion is not integrated or hinged from either housing.
U.S. Pat. No. 5,024,329 issued on Jun. 18, 1991 to Peter Grohrock discloses a wafer shipper that uses a hinged movable sidewall. This sidewall has multiple living hinges that push a wafer securing means against the wafers when the bottom housing is secured into the top housing. The interaction of closing the housing causes deformation of one part that makes contact with all of the wafers within the housing. In this patent the wafers are stored vertically. This cushion pushes from only one side and pushes the wafers against an outside wall where they are susceptible to damage. The top housing pushed down on the cushion instead of sliding on the cushion.
What is needed is a semiconductor wafer container with improvements in internal movement, side and top protection to the wafers, the improved wafer carrier has movable side walls that push against opposing sides of the wafer to eliminate movement of the wafer within the carrier. This pending application satisfies these requirements with novel improvements in the identified areas.